The present invention relates to a method for multicolor printing, preferably textile printing wherein the printing dyes are applied successively, preferably in mutually independent and separate printing stations in which each of the viscous printing dyes are cooled in order to obtain a non-viscous or set-off free condition before and during the application of the succeeding printing dye.
The term printing refers to the methods of printing in which a printing surface which does not necessarily have to consist of a textile material, but which can also consist of paper or similar materials, is provided with a multicolor print by successively leading the material to be printed through a number of printing stations in each of which a printing dye is applied, e.g. through a seri-graphical printing frame. The printing machine operates according to a seri-graphical principle, i.e. either by means of a roller-printing principle or a flat-printing principle.
For this purpose a number of various printing machines have been developed in which the materials to be printed are placed on supporting plates which are led along a number of printing stations in which a printing form is applied to the printing surface onto which the printing dye desired is applied. Furthermore, the printing station comprises a printing mechanism which is activated in order to print the pattern and the color which is special for each of the printing stations. Generally, 2-8 printing stations are in question. It is noted that the printing forms can be circular or planar.
The dyes used are generally rather viscous and they are applied in rather thick layers.
In order to achieve a relatively fast printing sequence a cooling technique may be used, e.g. similar to the one descibed in DE patent No. 2,944,560. Thus it becomes possible to obtain a stabilization of the printing dye between succeeding applications of different printing dyes. Such stabilization or fixation of the dyes is necessary in order to avoid the dyes mixing with one another. When cooled, it is possible to stabilize the printing area in such a way that the previously printed printing color before and during the application of the succeeding dye appears as a non-viscous or set-off free dye, thus avoiding any damage during its passage through the succeeding printing station.
However, by the known methods in which the printing color is fixed by cooling, the production capacity will be limited due to the isolating effect taking place through the material when a cooling is performed from the underside of the material. Accordingly, e.g. GB-A-1,489,593 discloses a method in which cooling is effected directly by means of a coolant which is sprayed directly onto the surface of the printing dye. However, this method gives a limited effect and the quality is not satisfying in all printings.